U.S. patent number 9,850,589 [Application Number 14/703,079] was granted by the patent office on 2017-12-26 for system and methods for electrochemical grinding with a screen.
This patent grant is currently assigned to UNITED TECHNOLOGIES CORPORATION. The grantee listed for this patent is UNITED TECHNOLOGIES CORPORATION. Invention is credited to Changsheng Guo, Raja Kountanya, Ying She, Daniel V. Viens.
United States Patent |
9,850,589 |
She , et al. |
December 26, 2017 |
System and methods for electrochemical grinding with a screen
Abstract
A system and methods are provided for electrochemical grinding a
workpiece. In one embodiment, a method includes controlling
potentials to grinding tool and the workpiece, controlling applying
electrolyte, and controlling grinding of the workpiece by the
grinding tool. The method may also include determining screen
replacement when there is sufficient metal plated.
Inventors: |
She; Ying (East Hartford,
CT), Kountanya; Raja (Manchester, CT), Guo;
Changsheng (South Windsor, CT), Viens; Daniel V. (East
Hartford, CT) |
Applicant: |
Name |
City |
State |
Country |
Type |
UNITED TECHNOLOGIES CORPORATION |
Farmington |
CT |
US |
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Assignee: |
UNITED TECHNOLOGIES CORPORATION
(Farmington, CT)
|
Family
ID: |
54367312 |
Appl.
No.: |
14/703,079 |
Filed: |
May 4, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20150322584 A1 |
Nov 12, 2015 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61991877 |
May 12, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25C
1/00 (20130101); C25C 7/02 (20130101); C25D
17/10 (20130101); C25F 7/00 (20130101); C25D
21/12 (20130101); C25C 7/06 (20130101); C25D
5/67 (20200801); C25C 7/00 (20130101); C25F
3/16 (20130101); C25D 5/22 (20130101) |
Current International
Class: |
C25D
5/22 (20060101); C25F 3/16 (20060101); C25C
1/00 (20060101); C25C 7/00 (20060101); C25C
7/02 (20060101); C25C 7/06 (20060101); C25D
17/10 (20060101); C25D 21/12 (20060101); C25F
7/00 (20060101) |
Field of
Search: |
;205/663 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hendricks; Keith
Assistant Examiner: Allen; Joshua
Attorney, Agent or Firm: Cantor Colburn LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application
No. 61/991,877 filed on May 12, 2014 and titled System and Methods
for Electrochemical Grinding with a Screen, the disclosure of which
is hereby incorporated by reference in its entirety.
Claims
What is claimed is:
1. An electrochemical grinding tool comprising: a voltage source
including an anode and a cathode, the anode being electrically
coupled to a workpiece; a grinding wheel having a grinding surface,
wherein the grinding wheel is electrically coupled to the cathode
of the voltage source, and wherein the grinding wheel includes
abrasive material on the grinding surface; and a screen coupled to
the grinding wheel, wherein the screen is configured to be
electrically coupled to the cathode of the voltage source, wherein
the screen is configured to recover material by electroplating
removed by the grinding wheel during electrochemical grinding,
wherein the screen encircles the grinding wheel and partially
encloses the abrasive material on the grinding surface, and wherein
a portion of the abrasive material extends radially outward beyond
the screen to allow the portion of the abrasive material to engage
with the workpiece.
2. The electrochemical grinding tool of claim 1, wherein the
abrasive material includes at least one of a nonconductive
material, diamond and aluminum oxide material.
3. The electrochemical grinding tool of claim 1, wherein the screen
is a metal mesh contoured to the grinding surface of the grinding
wheel.
4. The electrochemical grinding tool of claim 1, wherein the screen
is a metal mesh disk coupled to an outer surface of the grinding
wheel.
5. The electrochemical grinding tool of claim 1, wherein the screen
includes a plurality of openings to allow the portion of the
abrasive material of the grinding wheel to engage with the
workpiece.
6. The electrochemical grinding tool of claim 1, wherein the screen
is configured to be removable from the grinding wheel.
7. An electrochemical grinding system comprising: a grinding tool
including a voltage source including an anode and a cathode, the
anode being electrically coupled to a workpiece; a grinding wheel
having a grinding surface, wherein the grinding wheel is
electrically coupled to the cathode of the voltage source, and
wherein the grinding wheel includes abrasive material on the
grinding surface; and a screen coupled to the grinding wheel,
wherein the screen is configured to be electrically coupled to the
cathode of the voltage source, wherein the screen is configured to
recover material by electroplating removed by the grinding wheel
during electrochemical grinding, wherein the screen encircles the
grinding wheel and partially encloses the abrasive material on the
grinding surface, and wherein a portion of the abrasive material
extends radially outward beyond the screen to allow the portion of
the abrasive material to engage with the workpiece; and a
controller configured to control the grinding tool for
electrochemical grinding of the workpiece.
8. The electrochemical grinding system of claim 7, wherein the
abrasive material includes at least one of a nonconductive
material, diamond and aluminum oxide material.
9. The electrochemical grinding system of claim 7, wherein the
screen is a metal mesh contoured to the grinding surface of the
grinding wheel.
10. The electrochemical grinding system of claim 7, wherein the
screen is a metal mesh disk coupled an outer surface of the
grinding wheel.
11. The electrochemical grinding system of claim 7, wherein the
screen includes a plurality of openings to allow the portion of the
abrasive material of the grinding wheel to engage with the
workpiece.
12. The electrochemical grinding system of claim 7, wherein the
screen is configured to be removable from the grinding wheel.
13. A method for electrochemical grinding, the method comprising:
controlling a potential of a voltage source applied to a grinding
tool, wherein the grinding tool includes a screen coupled to a
grinding wheel having a grinding surface and abrasive material on
the grinding surface, wherein the voltage source includes an anode
and a cathode, and wherein the screen is electrically coupled to
the cathode of the voltage source; electrically coupling the anode
to a workpiece; electrically coupling the grinding wheel to the
cathode of the voltage source; encircling the grinding wheel with
the screen, wherein the screen partially encloses the abrasive
material on the grinding surface and wherein a portion of the
abrasive material extends radially outward beyond the screen to
allow the portion of the abrasive material to engage with the
workpiece; controlling a potential of the voltage source applied to
the workpiece; and controlling electrochemical grinding of the
workpiece by the grinding tool, wherein the screen is configured to
recover material by electroplating removed by the grinding wheel
during electrochemical grinding.
14. The method of claim 13, wherein potential applied to the screen
is different than the potential applied to the grinding wheel.
15. The method of claim 13, wherein controlling of potential
applied to the grinding tool includes measuring at least one of
current and potential of an electrolyte solution during
electrochemical grinding.
16. The method of claim 13, wherein controlling electrochemical
grinding includes controlling potential applied to the screen.
17. The method of claim 13, wherein controlling electrochemical
grinding includes adjusting one or more of the grinding speed,
angle and position of the grinding tool.
18. The method of claim 13, further comprising determining a
condition requiring screen replacement.
Description
FIELD
The present disclosure relates generally to grinding processes for
material removal, and more particularly to a system and methods for
electrochemical grinding with a screen element.
BACKGROUND
Grinding processes are employed to remove material from components
for manufacture and finishing. Conventional methods of finishing
and shaping aerospace components have employed grinding for high
strength materials. One processing limitation of traditional
grinding tools is the time required for grinding. Traditional
grinding methods may be less effective with hardened or temperature
resistant materials. While there have been improvements to grinding
techniques, tool life and surface quality continues to be a
concern. By way of example, traditional grinding may result in
stresses or defects in components.
BRIEF SUMMARY OF THE EMBODIMENTS
Disclosed and claimed herein are a system and methods for
electrochemical grinding. One embodiment is directed to an
electrochemical grinding tool. The electrochemical grinding tool
includes a grinding element having a grinding surface, wherein the
grinding element is configured to be electrically coupled to a
cathode of a voltage source. The grinding tool also includes a
screen coupled to the grinding element, wherein the screen is
configured to be electrically coupled to the cathode of the voltage
source, and wherein the screen is configured to recover material by
electroplating removed by the grinding element during
electrochemical grinding.
Another embodiment is directed to an electrochemical grinding
system. The grinding system includes a grinding tool including a
grinding element having a grinding surface, wherein the grinding
element is configured to be electrically coupled to a cathode of
the voltage source. The grinding system also includes a screen
coupled to the grinding element, wherein the screen is configured
to be electrically coupled to the cathode of the voltage source,
and wherein the screen is configured to recover material by
electroplating removed by the grinding element during
electrochemical grinding. The system also includes a controller
configured to control the grinding tool for electrochemical
grinding of a workpiece.
In one embodiment, a method is provided for electrochemical
grinding. The method includes controlling a potential of a voltage
source applied to a grinding tool, wherein the grinding tool
includes a screen coupled to a grinding element and wherein the
screen is electrically coupled to the cathode of the voltage
source. The method also includes controlling a potential of the
voltage source applied to a workpiece and controlling
electrochemical grinding of the workpiece by the grinding tool,
wherein the screen is configured to recover material by
electroplating removed by the grinding element during
electrochemical grinding.
Other aspects, features, and techniques will be apparent to one
skilled in the relevant art in view of the following detailed
description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The features, objects, and advantages of the present disclosure
will become more apparent from the detailed description set forth
below when taken in conjunction with the drawings in which like
reference characters identify correspondingly throughout and
wherein:
FIGS. 1A-1B depict graphical representations of a grinding tool
according to one or more embodiments;
FIGS. 2A-2C depict graphical representations of a grinding tool and
screen according to one or more embodiments;
FIG. 3 depicts a simplified system diagram according to one or more
embodiments; and
FIG. 4 depicts a process for electrochemical grinding according to
one or more embodiments.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
Overview and Terminology
One aspect of the disclosure relates to systems and methods for
grinding. In particular, systems and methods are provided for
electrochemical grinding. In one embodiment, an electrochemical
grinding tool is provided including a grinding element and a screen
coupled to the grinding element. According to other embodiments, a
system is provided for electrochemical grinding employing a
grinding tool with a screen. In other embodiments, methods are
provided for electrochemical grinding with a screen.
As used herein, the terms "a" or "an" shall mean one or more than
one. The term "plurality" shall mean two or more than two. The term
"another" is defined as a second or more. The terms "including"
and/or "having" are open ended (e.g., comprising). The term "or" as
used herein is to be interpreted as inclusive or meaning any one or
any combination. Therefore, "A, B or C" means "any of the
following: A; B; C; A and B; A and C; B and C; A, B and C". An
exception to this definition will occur only when a combination of
elements, functions, steps or acts are in some way inherently
mutually exclusive.
Reference throughout this document to "one embodiment," "certain
embodiments," "an embodiment," or similar term means that a
particular feature, structure, or characteristic described in
connection with the embodiment is included in at least one
embodiment. Thus, the appearances of such phrases in various places
throughout this specification are not necessarily all referring to
the same embodiment. Furthermore, the particular features,
structures, or characteristics may be combined in any suitable
manner on one or more embodiments without limitation.
Referring now to the figures, FIGS. 1A-1B depict graphical
representations of a grinding tool according to one or more
embodiments. FIG. 1A depicts electrochemical grinding tool 100
including grinding element 105 and screen 110. Grinding element 105
includes a grinding surface for removing material from one or more
components. According to one embodiment, grinding element 105 may
be a grinding wheel including abrasive material on the grinding
surface. Grinding element 105 is configured to be electrically
coupled to a cathode of a voltage source, such as potential
connection 115a. Screen 110 is electrically and mechanically
coupled to grinding element 105. According to one embodiment,
screen 110 may be configured to be electrically coupled to the
cathode of a voltage source. Screen 110 may be configured to
recover material by the electroplating removed by the grinding
element during electrochemical grinding.
Grinding tool 100 may be configured to remove material from one or
more elements, such as workpiece 120. By way of example, workpiece
120 may relate to one or more components, including but not limited
to blades, bearings, vanes, housings, and jet engine components in
general.
According to one embodiment, grinding tool 100 may be coupled to a
voltage source during electrochemical grinding. By way of example,
grinding tool 100 may be coupled to the cathode of a voltage source
and workpiece 120 may be coupled to an anode of the voltage source.
As shown in FIG. 1A, grinding element 105 is electrically coupled
to potential connection 115a and screen 110 is electrically coupled
to potential connection 115b of voltage source (e.g., cathode
connections). Workpiece 120 is electrically coupled to potential
connection 125 of a voltage source (e.g., anode connections).
According to one embodiment, screen 110 may be configured to
recover material removed by grinding element 105 during
electrochemical grinding. Screen 110 may be removeably coupled to
grinding element 105. FIG. 1B depicts a graphical representation of
grinding tool 100 in a disassembled view according to one or more
embodiments. According to one embodiment, grinding element 105 may
be a grinding wheel and screen 110 may be a metal mesh disk
configured to be coupled to a surface of grinding element 105.
Screen 110 may be removable to allow for a replacement screen to be
applied to grinding element 105. FIG. 1B depicts optional
connection element 130 which may be configured to couple screen 110
to a surface of grinding element 105.
Referring now to FIGS. 2A-2C, graphical representations of a
grinding tool and screen are depicted according to one or more
embodiments. According to one embodiment, FIGS. 2A-2C depict a
grinding tool having a screen configured to the contour of the
outer or grinding surface of a grinding element. The grinding tool
of FIGS. 2A-2C may be similarly coupled to potentials of a voltage
source as grinding tool 100 of FIGS. 1A-1B.
FIG. 2A depicts electrochemical grinding tool 200 including
grinding element 205 and screen 210. Grinding element 205 includes
grinding surface 215 for removing material from one or more
components. According to one embodiment, grinding element 205 may
be a grinding wheel including abrasive material on grinding surface
215. Grinding element 205 is configured to be electrically coupled
to a cathode of a voltage source. Screen 210 is coupled to grinding
element 205. According to one embodiment, screen 210 may be
configured to be electrically coupled to the cathode of a voltage
source. Screen 210 may be configured to recover material removed by
the electroplating by the grinding element during electrochemical
grinding.
FIG. 2B depicts electrochemical grinding tool 200 including
grinding element 205 and screen 210 removed from grinding element
205. According to one embodiment, screen 210 is a metal mesh
contoured to grinding surface 215 of the grinding element 205.
FIG. 2C depicts a cross-sectional representation of electrochemical
grinding tool 200 shown as grinding tool 201 including grinding
element 205 and screen 210, abrasive 216 applied to a grinding
surface and bonding material 220.
According to one embodiment, abrasive 216 includes at least one of
a nonconductive material, diamond and aluminum oxide material.
Abrasive 216 may be bonded to grinding element 205 by bonding
material 220. In certain embodiments, grinding element 205 includes
nonconductive material, diamond and aluminum oxide material, bonded
together by a bonding material such as nickel. According to another
embodiment, screen 210 includes a plurality of openings to allow
abrasive material 216 of grinding element 205 engage with a
workpiece (e.g., workpiece 120).
It should be appreciated that grinding tools 200 and 201 of FIGS.
2A-2C may be different embodiments of the grinding tool of FIGS.
1A-1B wherein elements and attributes of the grinding tools may be
similarly applied.
FIG. 3 depicts a simplified system diagram according to one or more
embodiments. According to one embodiment, system 300 may employ one
or more grinding tools described herein for electrochemical
grinding. Electrochemical grinding system 300 includes a grinding
tool 305 and controller 330.
According to one embodiment, grinding tool 305 includes grinding
element 310, such as a grinding wheel, having a grinding surface.
The grinding surface of grinding element 310 may include an
abrasive material. In certain embodiments, grinding element 310
includes nonconductive material, diamond and aluminum oxide
material, bonded together by a bonding material such as nickel. In
another embodiment, grinding tool 305 includes screen 315 coupled
to grinding element 310. Screen 315 is configured to recover
material by the electroplating removed by the grinding element 310
during electrochemical grinding.
Controller 330 may be configured to control grinding tool 305 for
electrochemical grinding of workpiece 360 including potential
applied and control of grinding tool 305. In one embodiment,
grinding tool 305 may be rotated by drive unit 320 via shaft 321.
Controller 330 may be configured to control drive unit 320 for
control of rotational speed for grinding tool 305. Controller 330
may be configured to control drive unit 320 in order to rotate one
or more grinding tools. Grinding element 310 is configured to be
electrically coupled to a cathode of the voltage source 340, as
shown by connection 335a. Screen 315 is configured to be
electrically coupled to a cathode of voltage source 340, as shown
by connection 335b. Workpiece 360 is configured to be electrically
coupled to an anode of voltage source 340, as shown by connection
345. According to one embodiment, screen 315 may have a different
electric potential than the grinding element 310. In certain
embodiments, screen 315 is insulated from grinding element 310 if
there are different potentials.
During electrochemical grinding, an electric current generated by
voltage source 340 is passed through electrolyte 355, which may be
a small gap (e.g., a 0.001'' gap) between workpiece 360 and
grinding tool 305. According to one embodiment, voltage source 340
can be a DC power supply of 4-14 volts, DC current can be 50-3000 A
with current density 500-1500 A/in.sup.2.
System 300 may include nozzle 350 configured to apply the
electrolyte 355 in the gap between workpiece 360 and grinding tool
305. Controller 330 may be configured to control electrochemical
grinding by applying an electrolyte in between workpiece 360 and
grinding tool 305. In other embodiments, system 300 may include
placing workpiece 360 and grinding tool 305 in a reservoir (not
shown) filled with a selected electrolyte and medium.
FIG. 4 depicts a process for electrochemical grinding according to
one or more embodiments. Process 400 may be employed by a
machine/apparatus for grinding, such as the system of FIG. 3.
Process 400 may include controlling a potential of a voltage source
applied to a grinding tool at block 405. A screen coupled to a
grinding element of a grinding tool may be electrically coupled to
the cathode of the voltage source and applied a potential. In one
embodiment, potential applied to the screen is different than the
potential applied to the grinding element. According to another
embodiment, controlling potential applied to the grinding tool at
block 405 includes measuring at least one of current and potential
of an electrolyte solution during electrochemical grinding.
At block 410, potential of the voltage source applied to a
workpiece is controlled.
At block 415, electrochemical grinding of the workpiece by the
grinding tool is controlled. During electrochemical grinding, the
screen is configured to recover material removed by the grinding
element during electrochemical grinding. Controlling
electrochemical grinding at block 415 can include controlling
potential applied to the screen.
Controlling electrochemical grinding at block 415 can include
applying electrolyte in between a grinding tool and workpiece. In
one of embodiment, the electrolyte may be sprayed by a nozzle. In
another embodiment, the electrolyte may be applied by placing the
workpiece and the grinding tool in a reservoir filled with a
selected electrolyte, for example, sodium chloride, sodium nitride
and rust inhibitor. A selected electrolyte may depend on material
to be ground. Controlling at block 415 may include selecting an
appropriate electrolyte and its medium to allow metal ions
generated from the workpiece (anode) in the electrochemical
grinding process not to form metal hydroxide/metal oxide rather to
exist in ions forms or coordinated with other ion groups in the
electrolyte medium so the metal ions travel to the cathode side and
electroplated on the cathode as the metal.
Controlling electrochemical grinding at block 415 can include
adjusting one or more of the grinding speed, angle and position of
the grinding tool. Positioning the grinding tool and the workpiece
may also include leave a gap between the grinding tool and the
workpiece, such as a distance is 0.001'' so that the electrolyte
can be applied during grinding.
Process 400 may optionally determine a condition requiring screen
replacement at block 420. During grinding, metals may accumulate on
the screen. During electrochemical grinding process 400, when
excessive metal is plated on the screen, the screen is replaced and
the metal may be recycled.
While this disclosure has been particularly shown and described
with references to exemplary embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the scope of
the claimed embodiments.
* * * * *